executor, privilege: require CONFIG privilege for is.cluster_config

[morgo]

What problem does this PR solve?

Issue Number: close #26062

Problem Summary:

The cluster_config table should require the CONFIG privilege. This is consistent with the behavior change in #25379 which requires CONFIG for SHOW CONFIG.

It makes sense to cherry pick to 5.1, but not 5.0; because the behavior in 5.0 was not established yet, and SHOW CONFIG still requires no privileges.

What is changed and how it works?

What's Changed:

Reading from the table information_schema.cluster_config now requires the CONFIG privilege.

Related changes

• Need to cherry-pick to the release branch

Check List

Tests

• Unit test

Side effects

• Breaking backward compatibility (yes, but for security)

Release note

• Reading from the table information_schema.cluster_config now requires the CONFIG privilege.

[morgo]

The username doesn't match the AuthUsername, which looks like a problem waiting to happen. I wrote this test but must have missed it :(

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• breeswish
• djshow832

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[djshow832]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 8bda59f

[ti-srebot]

cherry pick to release-5.1 in PR #26150